A three-dimensional picture of the delayed-detonation model of type Ia supernovae

Abstract

Aims. Deflagration models poorly explain the observed diversity of SNIa. Current multidimensional simulations of SNIa predict a significant amount of, so far unobserved, carbon and oxygen moving at low velocities. It has been proposed that these drawbacks can be resolved if there is a sudden jump to a detonation (delayed detonation), but these kinds of models have been explored mainly in one dimension. Here we present new three-dimensional delayed detonation models in which the deflagraton-to-detonation transition (DDT) takes place in conditions like those favored by one-dimensional models. Methods. We have used a smoothed-particle-hydrodynamics code adapted to follow all the dynamical phases of the explosion, with algorithms devised to handle subsonic as well as supersonic combustion fronts. The starting point was a centrally ignited C-O white dwarf of 1.38 M . When the average density on the flame surface reached ∼2−3 × 10 7 g cm −3 a detonation was launched. Results. The detonation wave processed more than 0.3 M of carbon and oxygen, emptying the central regions of the ejecta of unburned fuel and raising its kinetic energy close to the fiducial 10 51 erg expected from a healthy type Ia supernova. The final amount of 56 Ni synthesized also was in the correct range. However, the mass of carbon and oxygen ejected is still too high. Conclusions. The three-dimensional delayed detonation models explored here show an improvement over pure deflagration models, but they still fail to coincide with basic observational constraints. However, there are many aspects of the model that are still poorly known (geometry of flame ignition, mechanism of DDT, properties of detonation waves traversing a mixture of fuel and ashes). Therefore, it will be worth pursuing its exploration to see if a good SNIa model based on the three-dimensional delayed detonation scenario can be obtained.

High-resolution simulations of the head-on collision of white dwarfs

“…To that purpose, we used our 3D-SPH code (García-Senz & Bravo 2005;Bravo & García-Senz 2008) conveniently adapted to handle the present scenario.…”

The white dwarf’s carbon fraction as a secondary parameter of Type Ia supernovae

“…Interestingly, for the subclass of SN 2002cx-like SNe, pure deflagrations of Chandrasekhar-mass (Chandrasekhar 1931) WDs (Jordan et al 2012b;Kromer et al 2013;Fink et al 2014) in the SD channel match observables quite well . For normal SNe Ia, the most promising candidates are delayed detonations of Chandrasekhar-mass WDs in SD systems (e.g., Golombek & Niemeyer 2005;Gamezo et al 2005;Röpke & Niemeyer 2007;Bravo & García-Senz 2008;Jordan et al 2008;Townsley et al 2009;Jackson et al 2010;Seitenzahl et al 2011;Röpke et al 2012;Jordan et al 2012a;Seitenzahl et al 2013;Sim et al 2013), double detonations of sub-Chandrasekhar-mass WDs in SD and DD systems (e.g., Fink et al 2007Fink et al , 2010Moll & Woosley 2013), and violent mergers of sub-Chandrasekhar-mass WDs in DD systems (e.g., Pakmor et al 2012aPakmor et al ,b, 2013Moll et al 2014;Raskin et al 2014). A recent comparison to SN 2011fe (Röpke et al 2012) shows that disentangling different models is hard given the current predictions in the optical regime.…”

Modeling Type Ia supernova explosions

“…With the chosen parametrization of the DDT, the models reproduce the range of luminosities observed for normal SNe Ia. Thus, the delayed detonation scenario holds promise for explaining the main characteristics of these events [54,46,47,55,56]. A potential problem for this scenario, however, is that some population synthesis studies predict too few realizations of progenitor systems able to form a Chandrasekhar-mass WD to be compatible with the observed rate of normal SNe Ia [57].…”